Spring is a wonderful time to be a naturalist. There are new discoveries to be made every day — plants emerging, amphibians awakening, birds migrating back — you name it, there is something new to pause and observe. I have had the joy of leading bird walks at Evergreen Cemetery in Portland each day for the past two weeks and there are some questions that participants had daily, which I thought would be worth sharing here. Those are perhaps best summed up as “How is the spring shaping up?”

The only way I can describe this spring is: odd. We got a really early start, and then things really slowed down. I’m mostly talking about the bird migration we’ve been observing, in particular the long-distance song birds. Waterfowl migration peaked in April, and everything was about average or on time, while by late April, we were already getting reports of birds that typically don’t arrive until the first week or two of May. We’ll need a few more weeks to go through all the reports, but several warblers had new “early dates” — the earliest known occurrence of the species in Maine. A Bobolink smashed its record, and even some seabirds arrived early.

There is a well-documented pattern of species arriving earlier in response to climate change, but given the diversity of families and wintering locations, there seems to be more at play this year. Time will tell, but this is a good plug for readers to be contributing sightings, even from your backyards or local parks, of the plants and animals you see to iNaturalist or eBird to help track these phenomena.

Despite the early push, migration seemed to really slow down with all the low pressure systems we saw move through. Birds really like clear nights with a south (southwest) wind to help usher them north, but will often stop when facing bad weather. Even on days when conditions seemed perfect in Maine, birds were held up by rain passing south of New England. This was especially obvious on May 13, when BirdCast, which uses NEXRAD radar to estimate the number of birds in flight over a given area, estimated that more than 25 million birds flew over Maine that evening. For perspective, most nights see 2 million or fewer detected.

Unfortunately for birders, the next day was dead quiet as it seemed all the migrants took that opportunity to leave and continue their journey north, but a massive storm over the mid-Atlantic states stopped any new birds from filling in. Migration continues to trickle on, but as of this writing going into the last week of May, we are definitely behind average with the numbers moving through Maine.

While the birds are ebbing and flowing, plants in general seem a bit ahead of schedule as the warm temperatures and abundant rain have helped launch the growing season. We usually have completely unobscured views of warblers in Evergreen during the first week of the walk, and then by the end of the second week, the leaves are large enough to occlude a 4-5 inch warbler. This year, however, it seemed that warblers and vireos were being hidden by leaves by the end of the first week!

I’ll admit I don’t have the best beat on insects this year. After breaking my arm in March, my April activities were pretty limited and I suspect my usual detection of early mourning cloaks or black swallowtails was skewed. This is the first year of the Maine flower fly survey, so I was happy to start IDing
those in my yard, mostly visiting dandelions and violets on warm sunny days.

Tent caterpillars were notably absent, at least from our walks in Evergreen. As much as people dislike the non-native spongy moth and browntail moth, the native eastern and forest tent caterpillars are an important part of the ecosystem, and a favorite food source of birds like cuckoos. We only saw one black-billed cuckoo during our two weeks of walks at Evergreen. They are never a common species, but I didn’t see a single tent caterpillar nest anywhere in the woods; it’s possible those two things are related.

It is honestly still early and new birds and bugs are showing themselves still as I write this. There are fun discoveries to be had every day, and we’d love to see your sightings, especially the flower flies around you, showing up in iNaturalist!

Have you got a nature or wildlife question of your own? It doesn’t have to be about birds! Email questions to [email protected] and visit www.maineaudubon.org to learn more about birding, native plants, and programs and events focusing on Maine wildlife and habitat. Maine Audubon Staff Naturalist Doug Hitchcox and other naturalists lead free bird walks on Thursday mornings starting at 7 am, at Maine Audubon’s Gilsland Farm Audubon Sanctuary in Falmouth.